白马南地区长8_1砂岩成岩作用及其对储层的影响

Chang 8_1 Sandstone Diagenesis and the Influence on Chang 8_1 Reservoir of south Area of Baima,Ordos Basin

根据砂岩薄片、铸体薄片、扫描电镜、X-衍射和包裹体测温分析,研究了鄂尔多斯盆地西峰油田白马南地区长81储层的成岩作用特征,认为该区长81储层处于晚成岩A期阶段,压实作用和胶结作用强烈地破坏了砂岩的原生孔隙结构,溶蚀作用和破裂作用则有效地改善了砂岩的孔隙结构。该区长81储层发育次生孔隙相、泥质杂基压实相、自生碳酸盐胶结相和自生绿泥石胶结相,储层成岩相发育状况决定了孔隙结构的发育特征。发育次生孔隙相的砂岩具有较好的孔隙结构;而云母与泥质杂基压实相和碳酸盐胶结相发育的砂岩具有很差的孔隙结构。

Based on the date analysis of casting lamella, scan electron microscope. X-ray diffractions and vitrinite reflectance etc, the diagenesis include compaction and cementation, which belong to the ＂A＂ late diagenesis, that destroy the primary-texture of pore intensively and change the pore structure effectively on Chang81 reservoirs in south area of Baima in Xifeng oilfield in Eerduois Basin. The Chang81 reservoirs in south area of Baima develop secondary-pore facies.pelitic impurity compaction facies.authigemic carbonate cementation facies and authigenic chlorite cementation facies, which impact the the pore character of reservoirs： the sand develop secondary-pore facies that have the better pore texture, the pelitic impurity compaction facies and carbonate cementation facies develop in sand that have the lesser pore.